vibration/shaking while accelerating between 20-30 km/h

[aszaheer]

My car had broken engine mounts and recently it started vibrating pretty bad on idle and acceleration but would stop once the car started moving. I just had both my engine mounts replaced and decided to do all the front end bushes at the same time. The car has done around 188,000 km.

Since I got the work done the car still vibrates while accelerating though not as bad. It is most evident between 20-30 km/h and then stops after around 40 km/h. After that I can accelerate as much as I want with no vibration. I thought I was getting the vibration before coz of the engine mounts but the problem is still there after replacement. The mechanic said there might be a vacuum leak somewhere and even replaced a couple of pipes and checked for any loose connections which didn't really help.

I'm going back to the guy tomorrow to get the car checked properly and would like to know what you guys think could be causing the problem.

 

[Silverbird]

My car had broken engine mounts and recently it started vibrating pretty bad on idle and acceleration but would stop once the car started moving. I just had both my engine mounts replaced and decided to do all the front end bushes at the same time. The car has done around 188,000 km.

Since I got the work done the car still vibrates while accelerating though not as bad. It is most evident between 20-30 km/h and then stops after around 40 km/h. After that I can accelerate as much as I want with no vibration. I thought I was getting the vibration before coz of the engine mounts but the problem is still there after replacement. The mechanic said there might be a vacuum leak somewhere and even replaced a couple of pipes and checked for any loose connections which didn't really help.

I'm going back to the guy tomorrow to get the car checked properly and would like to know what you guys think could be causing the problem.

Hi Aszaheer,

You'll be needing a wheel alignment after doing the bushes. Get the wheel balance done - although I would have thought a balance issue would be more evident at highway speeds. That's that ruled out. Then go from there.

 

[Benboy]

You could (should) also check the harmonic Balancer and drive shaft(s). Won't do any harm to check the roundness of all wheels. Not unusual for a wheel to get out of round after hitting a pot hole etc.

 

[diysv6]

In passing, I have heard that aftermarket replacement engine mounts are being sold which are not oil-filled as per the VZ Holden originals.
I don't know if these aftermarket mounts are more "rigid" and allow some vibrations through the vehicle drivetrain.

(The front Z bar mount is also oil-filled, and aftermarket solid rubber replacements are around also. Then again, polyurethane bushes are offered as an aftermarket improvement for the front end. Don't know what I'd fit when replacement is needed).

 

[aszaheer]

Thanks for the responses guys, but it turned out to be something really easy to spot once the car was lifted. The transmission mount had split completely. Hopefully this might help someone in the future

 

[Silverbird]

Thanks for the responses guys, but it turned out to be something really easy to spot once the car was lifted. The transmission mount had split completely. Hopefully this might help someone in the future

Awesome - fixed well done. Thanks for following up to let us know.